蚓果芥乙烯受体基因的克隆与进化分析

Cloning and Evolutionary Analysis of Ethylene Receptor Gene in Neotorularia humilia(Brassicaceae)

采用已报道的十字花科植物乙烯受体基因(Ethylene Receptor 1,ETR1)通用引物,以蚓果芥基因组DNA为模板,经PCR分析BhETR1的多态性,进而从分子水平上阐明蚓果芥的进化特征。结果表明:(1)已克隆得到的14条ETR1基因序列,长度为1 644～1 661bp;经Bioedit软件比对,14条核苷酸序列之间相似性为93%～98%,蛋白氨基酸序列相似度为78%;采用DnaSP v5程序分别统计BhETR1序列多态性,发现14条BhETR1序列形成了14种单倍型。(2)从GenBank数据库下载蚓果芥近缘物种ETR1序列进行进化分析,系统发育分析表明蚓果芥14条ETR1序列形成3大分支;根据分支进化关系,每支中分别选取克隆2(c2)、克隆29(c29)、克隆35(c35)与拟南芥ETR1(AtETR1)和琴叶鼠耳芥ETR1(AlETR1)的序列进行比对,其一致性均为78%,说明BhETR1是一个乙烯受体类似(ETR1-like)基因,而蚓果芥自身14条序列的高度异质性表明蚓果芥的遗传背景相对复杂。

In order to elucidate the evolutionary characteristics of Neotorularia humilia,a pair of universal primers for Ethylene Receptor 1（ETR1） gene in Brassicaceae was chosen to amplify the homologous ETR1 in N.humilia by PCR,and 14 homologous sequences were cloned.Sequences were aligned by Bioedit and the similarities among these clones at nucleotide level were from 93% to 98%,and the similarities among these protein amino acid sequences were 78%.Nucleotide diversity was measured by DnaSP v5,and 14 DNA haplotypes were obtained in 1 644~1 661 bp fragments of BhETR1 in N.humilia.Furthermore,phylogenetic analysis revealed that 14 clones were classed into three clades,one representative clone from each clade（cloning 2,cloning 29,and cloning 35） was chosen to blast with ETR1 genes from Arabidopsis thaliana（L.） Heynh.and Arabidopsis lyrata.The nucleotide similarities were both 78%.These results suggest that BhETR1 is a ETR1-like gene,and the high heterogeneity among 14 BhETR1 sequences might be caused by the complex genome of N.humilia.